Hook n ladder 1 Posted July 14, 2020 Share Posted July 14, 2020 Would a 3.79 and 13 speed fuller be a decent setup for local dump work? Or would the ratio be too numerically low? The other choice would be a 3.98. Thanks in advance. Quote Link to comment Share on other sites More sharing options...
1965 Posted July 14, 2020 Share Posted July 14, 2020 (edited) The 3.98 is a lower gear, I had that in a truck & it did good pulling dump trailer. I think the 3.79 would be fine in a tractor, idk about a straight dump. truck had mp8 with 505hp. Edited July 14, 2020 by 1965 Quote Link to comment Share on other sites More sharing options...
Maxidyne Posted July 14, 2020 Share Posted July 14, 2020 Depends a lot on what weight the truck will operate at and where it's going. 1 Quote Link to comment Share on other sites More sharing options...
kscarbel2 Posted July 14, 2020 Share Posted July 14, 2020 2 hours ago, Hook n ladder 1 said: Would a 3.79 and 13 speed [overdrive?] fuller be a decent setup for local dump work? Or would the ratio be too numerically low? The other choice would be a 3.98. Thanks in advance. No, absolutely not. Quote Link to comment Share on other sites More sharing options...
Hook n ladder 1 Posted July 14, 2020 Author Share Posted July 14, 2020 It would be in a tractor. Max weight about 73,000lbs yes it would be a double over. Quote Link to comment Share on other sites More sharing options...
Maxidyne Posted July 14, 2020 Share Posted July 14, 2020 What's the steepest grade it''ll have to climb and will it go off road? Quote Link to comment Share on other sites More sharing options...
Freightrain Posted July 14, 2020 Share Posted July 14, 2020 ^^That was going to be my question. Might not be enough first gear to creep around in or back up in tight spaces without riding the clutch. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment Share on other sites More sharing options...
Hook n ladder 1 Posted July 14, 2020 Author Share Posted July 14, 2020 steepest probably 6% or so. Freightrain, I had the same thought. Quote Link to comment Share on other sites More sharing options...
j hancock Posted July 14, 2020 Share Posted July 14, 2020 Depending on exactly which 13 Fuller is being used, the 3.98 ratio will be better for you. Let's say your Fuller has the 13.13 1st gear ratio, as many do, combined with the 3.98 rear end will give an overall ratio of 52.25. A Mack X107 6 speed (lo hole) has a first gear ratio of 14.10 combined with a 4.17 rear (pretty common ratio) gives ratio of 58.97 and they play pretty well off road. Camelback suspension helps also in the dirt. 1 Quote JimIt doesn't cost anything to pay attention. Link to comment Share on other sites More sharing options...
mrsmackpaul Posted July 14, 2020 Share Posted July 14, 2020 (edited) If I understand this correctly you want a double over drive box on 3.79 or 3.98 and you want to pull 30 - 35 tons Unless its down hill and the load is very flat, as in sheet steel I doubt it would be very practical Or maybe you have 700 hp and 3000 pounds of torque Working gearing out on paper is a lot different than using it everyday I feel I would get sick of changing gears pretty quick and would much prefer to have the revs up a bit and just keep on poking along for a extra 1/4 of a hour each day Cummins used to have really good formulas for working this out and it took into account the height, the like terrain and the speed you wanted to travel at Im sure there must be some program or formula still out there to work this out Paul Edited July 14, 2020 by mrsmackpaul Quote Link to comment Share on other sites More sharing options...
Maxidyne Posted July 14, 2020 Share Posted July 14, 2020 3 hours ago, Hook n ladder 1 said: steepest probably 6% or so. Freightrain, I had the same thought. On the highway, maybe yes. But how about pulling up out of a pit or basement excavation? Quote Link to comment Share on other sites More sharing options...
Nobody454 Posted July 14, 2020 Share Posted July 14, 2020 (edited) my pete had 3.90 with an 18 spd and 550 cat. never once had a problem with local dump work, but a lot of that is the motor also my 12 mack had 3.55 and 13 spd with 445 mp8. never had a problem, but i've also done this for 20 years and keep out of most situations where i'll break something or get stuck too bad. 3.79 or 3.70 would be right between my two, they would be fine. 3.98 might be a little slow on the highway Edited July 14, 2020 by Nobody454 1 Quote Link to comment Share on other sites More sharing options...
1965 Posted July 14, 2020 Share Posted July 14, 2020 I agree with Nobody454, I had 12 CHU, 505, 18sp with 3.98. Worked well for running 55mph. I’d wished I had 3.55. My 18sp was the T318LR. was on tall rubber too. Quote Link to comment Share on other sites More sharing options...
davehummell Posted July 15, 2020 Share Posted July 15, 2020 I have a 3.90 rear in my b model and a double over triplex and on 81 I can cruse 75 mph. It helps I have a larger hp. engine than the old end673 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.